Apoptotic cell administration is detrimental in murine renal ischaemia reperfusion injury

BACKGROUND: Acute kidney injury induced by renal ischaemia reperfusion injury (IRI) is characterised by renal failure, acute tubular necrosis (ATN), inflammation and microvascular congestion. The administration of apoptotic cells (ACs) has been shown to reduce inflammation in various organs including the liver and kidney. This study explored whether AC administration prior to the induction of renal IRI was protective. FINDINGS: Renal IRI was induced in Balb/c mice by clamping the renal blood vessels for either 20, 24 or 25 minutes to induce mild, moderate or severe kidney dysfunction respectively. Renal function and injury was determined 24 hours following IRI by measurement of plasma creatinine and ATN scoring respectively. ACs were generated from Balb/c thymocytes and classified as either predominantly early or late apoptotic by Annexin-V and propidium iodide staining. Early AC administration prior to severe IRI had no influence on plasma creatinine or ATN severity. In contrast, administration of early or late ACs significantly worsened renal function in mice with mild or moderate renal IRI, respectively, compared to PBS treated controls, though ATN scores were comparable. Despite ACs exerting pro-coagulant effects, the worsening of renal function was not secondary to increased microvascular congestion, inferred by fibrin and platelet (CD41) deposition, or inflammation, assessed by neutrophil infiltration. CONCLUSIONS: Despite the AC-derived protection demonstrated in other organs, ACs do not protect mice from renal IRI. ACs may in fact further impair renal function depending on injury severity. These data suggest that AC-derived protection is not translationally relevant for patients with acute kidney injury induced by ischaemic injury. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12950-014-0031-6) contains supplementary material, which is available to authorized users

Fire as mediator of pine invasion: evidence from Patagonia, Argentina

Fire has been found to promote or halt biological invasions. Pine trees (genus Pinus) are highly invasive in the southern hemisphere and the effect of fire on their invasion ability is not clear. An analysis of Pinus spreading after wildfires in Patagonia reveals that there is a high risk of pines becoming invasive if ignition frequency increases in Patagonia. Also plantations could increase fire intensity and/or frequency in Patagonia, creating a potential positive feedback between invasion and wildfires. The effect of fires on pine invasion was modulated by precipitation. In areas where precipitation was lower than 800 mm fires did not promote pine invasion. However, in areas with higher precipitation there was a strong promotion of pine invasion by fire, after a lag time. These results show that fire, a disturbance more frequent now in the region, can promote pine invasion.Fil: Raffaele, Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Nuñez, Martin Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Eneström, J.. Lund University; SueciaFil: Blackhall, Melisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin